Solution processed oxygen and moisture barrier based on glass flakes for encapsulation of organic (opto-) electronic devices

Abstract

The concept of transparent barriers against oxygen and water based on polymer films filled with glass flakes is presented. Barriers are prepared by casting polyvinyl butyral (PVB) films containing glass flakes of different aspect ratios (ARs) at different loadings to systematically study the effect of these parameters on barrier quality and optical transmission. It is found that the glass flakes are distributed homogeneously in the PVB film, with an almost perfect orientation of the long axes of the platelets parallel to the film surface. For glass flakes having an AR of 2000, barrier films with optical transmittance exceeding 85% and water vapor transmission rates of 0.14 g m −2 d −1 are obtained at a glass loading of 25 vol%. The haze of the glass flake filled PVB films, which is mainly due to surface roughness of the films according to optical simulations, is reduced by coating a smoothing layer on top. The barrier properties persist even after 20 000 cycles of bending at a radius of 3 cm. The lifetime of organic solar cells increases to beyond 1000 h under damp heat conditions as well as under constant illumination, when the devices are encapsulated with the PVB/glass flake composite films.

Polyvinyl Alcohol and Nano-Clay Based Solution Processed Packaging Coatings

“…Moreover, the dispersion of the nano-clay platelets creates hindrances to the diffusing molecules [44], therefore, these hindrances are referred to as the tortuous path, and hence the permeation is decreased. The current experimental data are in good agreement with Bharadwaj's model of permeation for nanocomposites [45][46][47]. This permeation model suggests that the tortuous path of gas is influenced by film thickness, fractional volume, and aspect ratio of the particles with the ordered parameter "S".…”

“…Experimental results and the theoretical data suggested by Bhardwaj's model are almost similar or in close tolerance, as shown in Figure 7, which corroborate the experimental results. The current experimental data are in good agreement with Bharadwaj's model of permeation for nanocomposites [45][46][47]. This permeation model suggests that the tortuous path of gas is influenced by film thickness, fractional volume, and aspect ratio of the particles with the ordered parameter "S".…”

Gelatin- and Papaya-Based Biodegradable and Edible Packaging Films to Counter Plastic Waste Generation

“…Packaging plays an important role in protecting and extending the shelf life of food [ 7 ]. The prime features of packaging materials are low oxygen and moisture permittivity in ambient conditions, inertness towards food material, and chemical and mechanical stability in prescribed environmental conditions as per ASTM E460 [ 8 , 9 ]. Most of the materials used in the food packaging industry are non-biodegradable [ 10 ].…”

“…As a result, a huge amount of plastic waste is generated that needs extra care for its proper disposal. It is estimated that 30% of plastic waste generated comes from agriculture and packaging with a high risk of lagging agricultural system contamination [ 9 , 18 ]. Hence, the use of biodegradable materials is required, as they are suitable because of their physicochemical and mechanical properties to replace traditional plastics, thereby reducing the waste generation.…”

Process Parameter Optimization of a Polymer Derived Ceramic Coatings for Producing Ultra-High Gas Barrier

“…Many applications such as: solar cells [1] light-emitting diodes (LEDs) [2], organic transistors [3], and photodetectors [4] require encapsulating materials that should not only be transparent, but also an excellent barrier against the diffusion of oxygen and moisture at the same time [5][6][7][8][9][10]. Therefore, vacuum evaporated silica coatings have widely been used for this purpose [11].…”